Automated palletizing devices are known from the prior art that arrange a plurality of articles on a pallet and finally wrap the articles on the particular pallet in stretch film.
In order to be able to place a great number of articles on the particular pallet, it is preferable to arrange a plurality of layers of articles on top of each other on the particular pallet. The articles can form bundles with a plurality of beverage containers, for example. Such articles frequently have a complex geometry such that stacking of multiple layers is not always possible without creating problems with the stability of the entire pallet assembly. In particular during the transport of the pallet, it is necessary to be able to ensure a certain degree of stability for the pallet assembly in order to be able to exclude with certainty that the particular articles will topple.
In order to be able to increase the stability of the pallet assembly or to ensure sufficient stability for the pallet assembly it is known from the prior art to provide so-called intermediate layers for articles that are stacked on top of each other. Such intermediate layers can extend at least approximately across the entire width of the pallet so that all articles stand upon such an intermediate layer. Known intermediate layers are formed, for example, from paper, cardboard, paperboard, corrugated board, or from similar materials. Due to their stiffness, the intermediate layers provide a stable standing surface for the particular article layers arranged thereon on top of each other. It is also possible that a plurality of intermediate layers is provided for one level of the pallet or, as the case may be, that one level of the pallet is formed by a plurality of intermediate layers, on which the articles stand.
In automated processes of palletizing, intermediate layers must be available quickly and in great numbers. It is therefore known to have stacks of intermediate layers comprising a multitude of such intermediate layers.
Before the particular intermediate layers are placed on the pallet, it is necessary to remove individual intermediate layers from the stack, or more specifically, to separate the intermediate layers from the stack. For this purpose, there is a multitude of devices known from the prior art, by means of which such a removal of individual intermediate layers from the stack is carried out.
DE 10 2004 031 301 A1, for example, discloses such a device. The device of the DE patent application provides a stack of intermediate layers and picks them up by way of a gripper with suction cups. The intermediate layer is subsequently lifted up by the gripper and deposited on the particular pallet. After depositing, the gripper is retracted in order to pick up the next intermediate layer.
Practice has shown that individual intermediate layers of the stack can shift or become misaligned so that they are no longer aligned completely flush with each other, in particular after several consecutive removals of individual intermediate layers from the stack. If the intermediate layer is then positioned on the pallet, its position will not precisely conform to a desired position intended for the particular intermediate layer. It is also possible that the intermediate layer is not accurately picked up in the intended position by the gripper, which also results in an inaccurate positioning on the particular pallet. Pallets with inaccurately positioned intermediate layers on them can tend to be unstable.
It is in particular possible that such problems result with pallets for which the intermediate layers are formed as so-called half layers. In such a case, a number of intermediate layers or, as the case may be, of half layers, together form a level on the pallet, on which a plurality of articles stand. In order to be able to ensure the stability of the pallet, to prevent an undesired lateral protrusion of the half layers beyond the pallet, and to counter problems during palletizing, it would be desirable to have devices with which the intermediate layers or, as the case may be, the so-called half layers can be deposited on the particular pallet without problems and as accurately as possible or with which the intermediate layers or half layers are provided positioned as accurately as possible for being deposited on the particular pallet.
For this reason, one object of the present invention can be seen in providing a method and a device that contribute to the accurate positioning of a plurality of intermediate layers on associated pallets. In addition, the device is to have an uncomplicated construction. It should furthermore be easy to implement the method. The method and the device should moreover be characterized by a high throughput.